title: [Kussmaul's paradoxical pulse. Etiopathogenic aspects].
abstract: Paradoxical pulse (reduction in systolic blood pressure during inspiration) is a sign common to many pathological conditions affecting the heart and lungs. The aim of this paper was to determine its mechanism on the basis of recent publications in the literature, supported by personal clinical cases. Three cases of pulmonary embolism with paradoxical pulses of over 30 mm Hg are reported. In all three cases, cardiac and pulmonary function were normal before the embolism. The significant findings were a marked elevation in inspiratory transmural RA pressure (average 10 mm Hg), contrasting in one case with normal LV inspiratory transmural pressures. Two factors seem to play a role in the genesis of a paradoxical pulse: firstly, increased left ventricular afterload due to negative intrathoracic pressure during inspiration, and, secondly, a reduction of left ventricular compliance during inspiration related to mechanical interference between the two ventricles. In the absence of increased central venous pressure, increased left ventricular afterload probably plays the major role in the inspiratory reduction of peak systolic pressure (e.g. "physiological" paradoxical pulse, hypovolaemia, asthma). On the other hand, when central venous pressure is increased, the phenomenon of mechanical interference related to improved right ventricular filling during inspiration, added to increased left ventricular afterload, may result in very considerable paradoxical pulses (e.g. pulmonary embolism, cf. the cases reported: paradoxical pulses of over 30 mm Hg). Finally, certain pathological entities are associated with the greater role of mechanical interference (e.g. tamponade, constrictive pericarditis) for the principal causes, especially pulmonary embolism and pericardial effusion.
mesh_terms: D000368:Aged; D001794:Blood Pressure; D003187:Compliance; D005260:Female; D006346:Heart Septum / Q000503:physiopathology; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000503:physiopathology*; D011674:Pulse
vernacular_title: Le pouls paradoxal de Kussmaul. Aspects étiopathogéniques.